This invention relates to metal spot plating systems of the type disclosed in U.S. Pat. No. 3,723,283. This patent is herein incorporated by reference for its overall teachings of mechanisms to incrementally move a strip or web of metal through a plating head. When the web stops for an interval, plating heads close about and seal the web. A system of passageways and manifolds in the heads convey electrolyte plating fluid against the surface of the web. Apertured masks positioned between the web and the mask insure that plating fluid contacts the web only in the exact areas exposed by the apertures.
Throughput and efficiency are maximized by plating the selected areas as quickly as possible. Fast plating requires large quantities of electrolyte to flow over the work so as to refresh the metal ion supply. U.S. Pat. No. 3,723,283 discloses what has now become the standard configuration for directing a large flow of electrolyte at the area to be plated, namely, passageways positioned generally perpendicular to the web so as to spray electrolyte at the web with high flow rates.
It is also necessary to conduct electricity through the electrolyte. Typically the web is grounded and a positive wire or screen electrode is placed in the path of the electrolyte. This anode must be kept relatively small, however, so as to avoid blocking the flow of electrolyte. The present invention contemplates an improved arrangement.